1. Field of the Invention
This invention relates to a solid acid catalyst, more particularly to such a catalyst comprising active alumina and halogen supported thereon. The invention is still more particularly directed to a process for the re-activation of solid acid catalysts wherein the catalyst composition is thermally treated with an inert gas containing molecular oxygen (O.sub.2) and subjected to halogenation with a halogen compound entrained by an inert gas or a non-reducing gas.
2. Prior Art
The present inventors have previously disclosed in Japanese Laid-Open Patent Publication No. 56-28646 certain catalysts suitable for isomerizing aliphatic olefins having a relatively small amount of a branched structure to aliphatic olefins having a relatively large amount of a branched structure. This catalyst comprises an active alumina carrier and fluorine and chlorine supported thereon, the amounts of fluorine and chlorine being 0.3 to 1.0%, and 0.6 to 2.0%, respectively, based on the total weight of the catalyst composition.